This invention relates to turbine types of power plants and particularly to lobed mixers.
The mixing of two streams in a jet engine, particularly of the turbofan variety has been evolving over the past several years. For example, much work has been carried on to suppress sound of a turbofan engine by mixing the fan discharge flow with the core engine flow and lobe mixers have been heretofore utilized with much success. However, their design always included a compromise between mixing performance and pressure losses where a high degree of mixing is traded for pressure losses with consequential good sound suppression and poor engine performance and a low degree of mixing resulted in just the converse.
This invention contemplates improving lobed mixers by scalloping the side walls of the mixer, thereby increasing the mixing length and introducing trailing vortex sheets. This has proven to not only increase sound suppression but also improve propulsion performance or at least did not deteriorate it.